Central airways obstruction in carcinoma of the bronchus treated by radiotherapy: a study of pulmonary function.

A battery of lung function tests was performed on 28 patients with carcinoma of the bronchus, before radiotherapy, six weeks later, and at three months. Twenty-five had evidence of ariways obstruction, though only five had a forced expiratory ratio of less than 50%. Nine were shown to have obstruction to a main or lobar bronchus, while 11 definitely did not, but the only significant difference in lung function between groups was in the residual volume calculated from single breath helium dilution. Eight of ten cases of squamous cell carcinoma were central, and seven of these obstructive. Of seven cases with undifferentiated cells only two were central (p less than 0.05) and one obstructive. Breathlessness on presentation was significantly more common in patients with central tumours (6/12) than those with peripheral lesions (1/8), and all six breathless patients with central tumours claimed that this symptom improved after radiotherapy. Radiotherapy may have a palliative effect for breathlessness in patients with central airways obstruction due to tumour.